1. Field of the Invention
The present invention generally relates to a liquid crystal module. More specifically, the present invention relates to a liquid crystal module having U-shaped cold cathode tubes.
2. Background Information
With a conventional directly backlit liquid crystal module, a light reflecting sheet is provided on an inside of a rear frame. A plurality of cold cathode tubes parallel to each other is arranged over the light reflecting sheet. An optical sheet and a liquid crystal panel are disposed above the cold cathode tubes.
Some of the directly backlit liquid crystal modules have straight cold cathode tubes installed, and some have U-shaped cold cathode tubes installed. Among the latter (liquid crystal modules in which U-shaped cold cathode tubes are installed), there are some in which a plurality of U-shaped cold cathode tubes having different widths (e.g., bending pitch) of the U-shaped bent parts are installed in order to reduce variance in brightness, etc.
The U-shaped cold cathode tubes of varying width of the U-shaped bent parts are produced by bending in a U-shape straight cold cathode tubes whose overall length varies by the difference in their widths of the U-shaped bent parts, so that regardless of how wide the U-shaped bent parts are, the length from the ends of the U-shaped cold cathode tube to the U-shaped bent part is always the same.
Meanwhile, there has been a proposal for a direct backlight in which the cold cathode tubes have a configuration which forms an approximate rectangle from one tube end to the other, so that short tube segments are present in substantially the same length in left and right short tube segment areas. As a result, light emission densities of the left and right short tube segment areas are substantially the same, and the brightness is uniform at the left and right ends as seen through a diffuser plate (see Japanese Laid-Open Patent Application No. 2004-335378, for example).
There has also been proposed a backlight assembly having a holding container, cold cathode tubes, a reflector plate and an optical member. The holding container includes a base part and side parts extending from the base part and forming a holding space. The cold cathode tubes are held in the holding container and generate light. The reflector plate is disposed between the cold cathode tubes and the base part of the holding container and includes a protrusion that protrudes in the direction of the cold cathode tubes and supports the cold cathode tubes. The optical member is disposed on top of the cold cathode tubes (see Japanese Laid-Open Patent Application No. 2006-216540, for example).
Furthermore, there has been proposed a backlight unit having a fluorescent lamp, a support structure and a reflecting sheet. The support structure has a rear sheet metal piece disposed substantially parallel to the fluorescent lamp and facing the fluorescent lamp, and a lamp holder that is attached to the rear sheet metal piece and supports the fluorescent lamp. The reflecting sheet is disposed on the side of the rear sheet metal piece opposite the fluorescent lamp and engages with the support structure. The reflecting sheet is capable of parallel movement in a direction parallel to the side of the rear sheet metal piece opposite the fluorescent lamp with respect to the support structure (see Japanese Laid-Open Patent Application 2006-114445, for example).
However, with a conventional liquid crystal module having U-shaped cold cathode tubes produced such that the length from the ends to the U-shaped bent part is the same regardless of how width the U-shaped bent parts are (regardless of the bending pitch), the manufacturing cost increases because a number of straight cold cathode tubes whose overall length varies by the difference in the widths of the U-shaped bent parts have to be readied and bent.
This problem is difficult to be solved by applying the technology of Japanese Laid-Open Patent Application No. 2004-335378, in which cold cathode tubes are bent in an approximately rectangular shape and the short tube segments of the cold cathode tubes are present in substantially the same length in the left and right short tube segment areas, to produce U-shaped cold cathode tubes of different U-shaped bent part widths.
Also, since the techniques in Japanese Laid-Open Patent Application Nos. 2006-216540 and 2006-114445 do not involve the use of U-shaped cold cathode tubes of different U-shaped bent part widths, the above-mentioned problem is difficult to be solved by applying these techniques.
In view of the above, it will be apparent to those skilled in the art from this disclosure that there exists a need for an improved liquid crystal module. This invention addresses this need in the art as well as other needs, which will become apparent to those skilled in the art from this disclosure.